Figure 1.

Caspase-1-dependent secretion of IL-1β in UV-B-stimulated HCE-2 and primary HCE cells. HCE-2 cells were primed for 24 hours either with LPS (1 µg/mL; A) or TNF-α (10 ng/mL; B) followed by irradiation with UV-B (0.2 J/cm²). The secretion of IL-1β was measured by the ELISA method from HCE cell culture media for 24 hours after the UV-B irradiation. The levels of IL-1β were combined from three independent experiments with five to six parallel samples per group. Additionally, levels of IL-1β and LDH were measured from the primary HCE cell culture media from eight donors with one to three parallel samples per donor (C-D). Alternatively, HCE-2 (E) or primary HCE (F-G) cells were pretreated with the caspase-1 inhibitor (200 µM [E] or 100 µM [F-G] for 1 hour before the UV-B exposure). IL-1β data from HCE-2 cells (E) have been combined from three independent experiments each with 10 to 12 parallel samples. IL-1β and LDH data from cultured primary HCE cells (F-G) have been combined from four donors with one to two parallel samples per donor. All data are presented as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ns = not significant, Mann-Whitney U-test; pHCE = primary HCE cells; casp.1 inh. = caspase-1 inhibitor.